Question

упростите 1-2cost*sint/(cost-sint)^2

Answer 1

1-2cost*sint/(cost-sint)^2=sint^2+cosnt^2-2cosntsint/(cosnt-sint)^2=1

Answer 2

$frac{1-2costcdot sint}{(cost-sint)^2} = frac{1-sin2t}{cos^2t-2costcdot sint+sin^2t} = frac{1-sin2t}{(sin^2t+cos^2t)-2costcdot sint} =\\= frac{1-sin2t}{1-sin2t} =1$